Table 2.
Characteristics of patients with or without asthma–COPD overlap syndrome
| Characteristics | Total (n=1,008) | ACOS defined by syndromic features and FEV1 variability ≥12% and ≥200 mL
|
ACOS defined by syndromic features and FEV1 variability ≥12% and ≥400 mL
|
||||
|---|---|---|---|---|---|---|---|
| ACOS (n=93) |
COPD alone (n=915) |
P-value | ACOS (n=42) |
COPD alone (n=966) |
P-value | ||
| Sex (male) | 937 (93.0) | 84 (90.3) | 853 (93.2) | 0.288* | 38 (90.5) | 899 (93.1) | 0.531* |
| Age at enrollment (years) | 73.5±8.3 | 69.2±9.8 | 73.9±8.0 | <0.001# | 66.9±11.1 | 73.8±8.0 | <0.001# |
| Height (cm) | 163.0±6.9 | 164.4±7.9 | 162.9±6.8 | 0.071# | 166.4±8.2 | 162.9±6.8 | 0.001# |
| Weight (kg) | 59.4±10.9 | 62.0±11.2 | 59.1±10.8 | 0.014# | 63.4±12.3 | 59.2±10.8 | 0.015# |
| BMI (kg/m2) | 22.3±3.5 | 22.8±3.4 | 22.2±3.5 | 0.092# | 22.8±3.7 | 22.3±3.4 | 0.329# |
| COPD duration (months) | 69.0±51.4 | 54.0±52.0 | 70.5±51.1 | 0.003# | 39.3±31.1 | 70.3±51.7 | <0.001# |
| Smoking status | |||||||
| Current smoker | 146 (14.5) | 14 (15.1) | 0.877* | 8 (19.0) | 0.372* | ||
| Ex-smoker | 862 (85.5) | 79 (84.9) | 34 (81.0) | ||||
| Pack-years | 56.9±31.3 | 46.0±27.7 | 58.1±31.5 | <0.001# | 40.6±21.9 | 57.7±31.5 | <0.001# |
| Lung function | |||||||
| FEV1/FVC (%) | 50.9±12.9 | 54.8±10.9 | 50.4±13.0 | <0.001# | 56.5±11.4 | 50.6±12.9 | 0.004# |
| % predicted FEV1 | 56.7±21.1 | 64.2±18.2 | 56.0±21.2 | <0.001# | 69.6±20.1 | 56.2±21.0 | <0.001# |
| % predicted FVC | 87.5±20.8 | 94.0±17.8 | 86.8±21.0 | <0.001# | 98.8±16.1 | 87.0±20.9 | <0.001# |
| GOLD stage | |||||||
| I | 148 (14.7) | 17 (18.3) | <0.001‡ | 13 (31.0) | <0.001‡ | ||
| II | 463 (45.9) | 58 (62.4) | 22 (52.4) | ||||
| III | 285 (28.3) | 15 (16.1) | 6 (14.3) | ||||
| IV | 112 (11.1) | 3 (3.2) | 1 (2.4) | ||||
| Treatment for COPD or asthma | |||||||
| Any treatment | 988 (98.0) | 91 (97.8) | 897 (98.0) | 0.706* | 42 (100.0) | 946 (97.9) | 1.000* |
| SAMA | 10 (1.0) | 1 (1.1) | 9 (1.0) | 0 (0.0) | 10 (1.0) | ||
| SABA | 120 (11.9) | 12 (12.9) | 108 (11.8) | 5 (11.9) | 115 (11.9) | ||
| LAMA | 578 (57.3) | 50 (53.8) | 528 (57.7) | 22 (52.4) | 556 (57.6) | ||
| LABA | 140 (13.9) | 6 (6.5) | 134 (14.6) | 2 (4.8) | 138 (14.3) | ||
| LABA/LAMA | 199 (19.7) | 10 (10.8) | 189 (20.7) | 5 (11.9) | 194 (20.1) | ||
| ICS | 75 (7.4) | 8 (8.6) | 67 (7.3) | 3 (7.1) | 72 (7.5) | ||
| ICS/LABA | 404 (40.1) | 64 (68.8) | 340 (37.2) | 31 (73.8) | 373 (38.6) | ||
| Expectorant | 250 (24.8) | 10 (10.8) | 240 (26.2) | 6 (14.3) | 244 (25.3) | ||
| Xanthine derivatives | 166 (16.5) | 13 (14.0) | 153 (16.7) | 7 (16.7) | 159 (16.5) | ||
| Leukotriene receptor antagonist | 95 (9.4) | 23 (24.7) | 72 (7.9) | 12 (28.6) | 83 (8.6) | ||
| Anti-IgE antibody | 4 (0.4) | 0 (0.0) | 4 (0.4) | 0 (0.0) | 4 (0.4) | ||
| Systemic steroid (oral/injection) | 32 (3.2) | 2 (2.2) | 30 (3.3) | 2 (4.8) | 30 (3.1) | ||
| Oxygen therapy | 132 (13.1) | 2 (2.2) | 130 (14.2) | 1 (2.4) | 131 (13.6) | ||
| Ventilatory support/surgical therapy | 5 (0.5) | 0 (0.0) | 5 (0.5) | 0 (0.0) | 5 (0.5) | ||
| Other | 66 (6.5) | 5 (5.4) | 61 (6.7) | 3 (7.1) | 63 (6.5) | ||
Notes: Data are presented as n (%) or mean ± standard deviation.
*
Fisher’s exact test.
#
Student’s t-test.
‡
Wilcoxon rank sum test.
Abbreviations: ACOS, asthma–COPD overlap syndrome; BMI, body mass index; FEV1, forced expiratory volume in 1 second; FVC, forced vital capacity; GOLD, Global Initiative for Chronic Obstructive Lung Disease; ICS, inhaled corticosteroid; IgE, immunoglobulin E; LABA, long-acting beta agonist; LAMA, long-acting muscarinic antagonist; SABA, short-acting beta agonist; SAMA, short-acting muscarinic antagonist.